The signal path of a receiver is coupled to a signal source. The operating point of this signal source is often not the same one that the receiver needs. For instance, an antenna is frequently operated at ground level, or a photomultiplier tube (PMT) is operated at approximately 2000V. For this reason, a high-pass filter is used in order to separate the operating points. This high-pass filter is, in principle, a capacitor. If a low-pas filter is installed on one side of the capacitor in order to prescribe an operating point, this is also called a bias tee. Such an arrangement is prone to signal distortions.